Search Results for author: Dimitrios Kollias

Found 34 papers, 4 papers with code

Uncertainty-guided Contrastive Learning for Single Source Domain Generalisation

no code implementations12 Mar 2024 Anastasios Arsenos, Dimitrios Kollias, Evangelos Petrongonas, Christos Skliros, Stefanos Kollias

In the context of single domain generalisation, the objective is for models that have been exclusively trained on data from a single domain to demonstrate strong performance when confronted with various unfamiliar domains.

Contrastive Learning

COVID-19 Computer-aided Diagnosis through AI-assisted CT Imaging Analysis: Deploying a Medical AI System

no code implementations10 Mar 2024 Demetris Gerogiannis, Anastasios Arsenos, Dimitrios Kollias, Dimitris Nikitopoulos, Stefanos Kollias

Computer-aided diagnosis (CAD) systems stand out as potent aids for physicians in identifying the novel Coronavirus Disease 2019 (COVID-19) through medical imaging modalities.

Domain adaptation, Explainability & Fairness in AI for Medical Image Analysis: Diagnosis of COVID-19 based on 3-D Chest CT-scans

1 code implementation4 Mar 2024 Dimitrios Kollias, Anastasios Arsenos, Stefanos Kollias

The paper presents the DEF-AI-MIA COV19D Competition, which is organized in the framework of the 'Domain adaptation, Explainability, Fairness in AI for Medical Image Analysis (DEF-AI-MIA)' Workshop of the 2024 Computer Vision and Pattern Recognition (CVPR) Conference.

Domain Adaptation Fairness

The 6th Affective Behavior Analysis in-the-wild (ABAW) Competition

no code implementations29 Feb 2024 Dimitrios Kollias, Panagiotis Tzirakis, Alan Cowen, Stefanos Zafeiriou, Irene Kotsia, Alice Baird, Chris Gagne, Chunchang Shao, Guanyu Hu

This paper describes the 6th Affective Behavior Analysis in-the-wild (ABAW) Competition, which is part of the respective Workshop held in conjunction with IEEE CVPR 2024.

Action Unit Detection Arousal Estimation +1

Distribution Matching for Multi-Task Learning of Classification Tasks: a Large-Scale Study on Faces & Beyond

no code implementations2 Jan 2024 Dimitrios Kollias, Viktoriia Sharmanska, Stefanos Zafeiriou

Multi-Task Learning (MTL) is a framework, where multiple related tasks are learned jointly and benefit from a shared representation space, or parameter transfer.

 Ranked #1 on Facial Expression Recognition (FER) on AffectNet (Accuracy (7 emotion) metric, using extra training data)

Action Unit Detection Face Recognition +3

BTDNet: a Multi-Modal Approach for Brain Tumor Radiogenomic Classification

no code implementations5 Oct 2023 Dimitrios Kollias, Karanjot Vendal, Priyanka Gadhavi, Solomon Russom

Brain tumors pose significant health challenges worldwide, with glioblastoma being one of the most aggressive forms.

Data Augmentation

ABAW: Valence-Arousal Estimation, Expression Recognition, Action Unit Detection & Emotional Reaction Intensity Estimation Challenges

no code implementations2 Mar 2023 Dimitrios Kollias, Panagiotis Tzirakis, Alice Baird, Alan Cowen, Stefanos Zafeiriou

The fifth Affective Behavior Analysis in-the-wild (ABAW) Competition is part of the respective ABAW Workshop which will be held in conjunction with IEEE Computer Vision and Pattern Recognition Conference (CVPR), 2023.

Action Unit Detection Arousal Estimation

FaceRNET: a Facial Expression Intensity Estimation Network

no code implementations1 Mar 2023 Dimitrios Kollias, Andreas Psaroudakis, Anastasios Arsenos, Paraskevi Theofilou

This paper presents our approach for Facial Expression Intensity Estimation from videos.

A Deep Neural Architecture for Harmonizing 3-D Input Data Analysis and Decision Making in Medical Imaging

no code implementations1 Mar 2023 Dimitrios Kollias, Anastasios Arsenos, Stefanos Kollias

Harmonizing the analysis of data, especially of 3-D image volumes, consisting of different number of slices and annotated per volume, is a significant problem in training and using deep neural networks in various applications, including medical imaging.

COVID-19 Diagnosis Decision Making

Multi-Label Compound Expression Recognition: C-EXPR Database & Network

no code implementations CVPR 2023 Dimitrios Kollias

In this paper we present an in-the-wild A/V database, C-EXPR-DB, consisting of 400 videos of 200K frames, annotated in terms of 13 compound expressions, valence-arousal emotion descriptors, action units, speech, facial landmarks and attributes.

 Ranked #1 on Facial Expression Recognition (FER) on RAF-DB (Avg. Accuracy metric)

Emotion Recognition Facial Expression Recognition (FER) +1

ABAW: Learning from Synthetic Data & Multi-Task Learning Challenges

no code implementations3 Jul 2022 Dimitrios Kollias

In more detail: i) s-Aff-Wild2 -- a static version of Aff-Wild2 database -- has been constructed and utilized for the purposes of the Multi-Task-Learning Challenge; and ii) some specific frames-images from the Aff-Wild2 database have been used in an expression manipulation manner for creating the synthetic dataset, which is the basis for the Learning from Synthetic Data Challenge.

Action Unit Detection Arousal Estimation +1

AI-MIA: COVID-19 Detection & Severity Analysis through Medical Imaging

no code implementations9 Jun 2022 Dimitrios Kollias, Anastasios Arsenos, Stefanos Kollias

This paper presents the baseline approach for the organized 2nd Covid-19 Competition, occurring in the framework of the AIMIA Workshop in the European Conference on Computer Vision (ECCV 2022).

MixAugment & Mixup: Augmentation Methods for Facial Expression Recognition

no code implementations9 May 2022 Andreas Psaroudakis, Dimitrios Kollias

We further investigate the combination of dropout with Mixup and MixAugment, as well as the combination of other data augmentation techniques with MixAugment.

Data Augmentation Facial Expression Recognition +1

ABAW: Valence-Arousal Estimation, Expression Recognition, Action Unit Detection & Multi-Task Learning Challenges

no code implementations22 Feb 2022 Dimitrios Kollias

This paper describes the third Affective Behavior Analysis in-the-wild (ABAW) Competition, held in conjunction with IEEE International Conference on Computer Vision and Pattern Recognition (CVPR), 2022.

Action Unit Detection Arousal Estimation +1

MIA-COV19D: COVID-19 Detection through 3-D Chest CT Image Analysis

no code implementations14 Jun 2021 Dimitrios Kollias, Anastasios Arsenos, Levon Soukissian, Stefanos Kollias

In this paper we present the COV19-CT-DB database which is annotated for COVID-19, consisting of about 5, 000 3-D CT scans, We have split the database in training, validation and test datasets.

COVID-19 Diagnosis Disease Prediction

Analysing Affective Behavior in the second ABAW2 Competition

no code implementations14 Jun 2021 Dimitrios Kollias, Irene Kotsia, Elnar Hajiyev, Stefanos Zafeiriou

The Affective Behavior Analysis in-the-wild (ABAW2) 2021 Competition is the second -- following the first very successful ABAW Competition held in conjunction with IEEE FG 2020- Competition that aims at automatically analyzing affect.

Action Unit Detection Arousal Estimation

Distribution Matching for Heterogeneous Multi-Task Learning: a Large-scale Face Study

no code implementations8 May 2021 Dimitrios Kollias, Viktoriia Sharmanska, Stefanos Zafeiriou

Based on this approach, we build FaceBehaviorNet, the first framework for large-scale face analysis, by jointly learning all facial behavior tasks.

Ranked #5 on Facial Expression Recognition (FER) on RAF-DB (Avg. Accuracy metric, using extra training data)

Action Unit Detection Attribute +6

Affect Analysis in-the-wild: Valence-Arousal, Expressions, Action Units and a Unified Framework

no code implementations29 Mar 2021 Dimitrios Kollias, Stefanos Zafeiriou

Affect analysis and recognition can be seen as a dual knowledge generation problem, involving: i) creation of new, large and rich in-the-wild databases and ii) design and training of novel deep neural architectures that are able to analyse affect over these databases and to successfully generalise their performance on other datasets.

Action Unit Detection Emotion Classification +1

Analysing Affective Behavior in the First ABAW 2020 Competition

no code implementations30 Jan 2020 Dimitrios Kollias, Attila Schulc, Elnar Hajiyev, Stefanos Zafeiriou

For the Challenges, we provide a common benchmark database, Aff-Wild2, which is a large scale in-the-wild database and the first one annotated for all these three tasks.

Action Unit Detection Arousal Estimation +1

Face Behavior a la carte: Expressions, Affect and Action Units in a Single Network

no code implementations15 Oct 2019 Dimitrios Kollias, Viktoriia Sharmanska, Stefanos Zafeiriou

We present the first and the largest study of all facial behaviour tasks learned jointly in a single multi-task, multi-domain and multi-label network, which we call FaceBehaviorNet.

Emotion Recognition Few-Shot Learning

Interpretable Deep Neural Networks for Facial Expression and Dimensional Emotion Recognition in-the-wild

no code implementations14 Oct 2019 Valentin Richer, Dimitrios Kollias

In this project, we created a database with two types of annotations used in the emotion recognition domain : Action Units and Valence Arousal to try to achieve better results than with only one model.

Emotion Recognition Generative Adversarial Network

Interpretable Deep Neural Networks for Dimensional and Categorical Emotion Recognition in-the-wild

no code implementations13 Oct 2019 Xia Yicheng, Dimitrios Kollias

This project focuses on extending the emotion recognition database, and training the CNN + RNN emotion recognition neural networks with emotion category representation and valence \& arousal representation.

Emotion Recognition

Image Generation and Recognition (Emotions)

no code implementations13 Oct 2019 Hanne Carlsson, Dimitrios Kollias

Generative Adversarial Networks (GANs) were proposed in 2014 by Goodfellow et al., and have since been extended into multiple computer vision applications.

Image Generation

Emotion Generation and Recognition: A StarGAN Approach

no code implementations12 Oct 2019 Aritra Banerjee, Dimitrios Kollias

The main idea of this ISO is to use StarGAN (A type of GAN model) to perform training and testing on an emotion dataset resulting in a emotion recognition which can be generated by the valence arousal score of the 7 basic expressions.

4k Emotion Recognition +1

Aff-Wild Database and AffWildNet

1 code implementation11 Oct 2019 Mengyao Liu, Dimitrios Kollias

VGGFace, ResNet, DenseNet with the corresponding pre-trained model for CNN block and LSTM, GRU, IndRNN, Attention mechanism for RNN block are experimented aiming to find the best combination.

Transfer Learning

AffWild Net and Aff-Wild Database

no code implementations11 Oct 2019 Alvertos Benroumpi, Dimitrios Kollias

The purpose of this project is to study the previous work that was done for the "in the wild" emotions recognition concept, design a new dataset which has as a standard the "Aff-wild" database, implement new deep learning models and evaluate the results.

Exploiting multi-CNN features in CNN-RNN based Dimensional Emotion Recognition on the OMG in-the-wild Dataset

no code implementations3 Oct 2019 Dimitrios Kollias, Stefanos Zafeiriou

This paper presents a novel CNN-RNN based approach, which exploits multiple CNN features for dimensional emotion recognition in-the-wild, utilizing the One-Minute Gradual-Emotion (OMG-Emotion) dataset.

Arousal Estimation Emotion Recognition +1

Expression, Affect, Action Unit Recognition: Aff-Wild2, Multi-Task Learning and ArcFace

no code implementations25 Sep 2019 Dimitrios Kollias, Stefanos Zafeiriou

The need to collect and annotate diverse in-the-wild datasets has become apparent with the rise of deep learning models, as the default approach to address any computer vision task.

Action Unit Detection Arousal Estimation +3

Deep Neural Network Augmentation: Generating Faces for Affect Analysis

no code implementations12 Nov 2018 Dimitrios Kollias, Shiyang Cheng, Evangelos Ververas, Irene Kotsia, Stefanos Zafeiriou

This paper presents a novel approach for synthesizing facial affect; either in terms of the six basic expressions (i. e., anger, disgust, fear, joy, sadness and surprise), or in terms of valence (i. e., how positive or negative is an emotion) and arousal (i. e., power of the emotion activation).

Ranked #6 on Facial Expression Recognition (FER) on RAF-DB (Avg. Accuracy metric, using extra training data)

Data Augmentation Face Generation +1

A Multi-Task Learning & Generation Framework: Valence-Arousal, Action Units & Primary Expressions

no code implementations11 Nov 2018 Dimitrios Kollias, Stefanos Zafeiriou

Various approaches have been proposed for: i) discrete emotion recognition in terms of the primary facial expressions; ii) emotion analysis in terms of facial Action Units (AUs), assuming a fixed expression intensity; iii) dimensional emotion analysis, in terms of valence and arousal (VA).

Emotion Recognition Generative Adversarial Network +2

Aff-Wild2: Extending the Aff-Wild Database for Affect Recognition

1 code implementation11 Nov 2018 Dimitrios Kollias, Stefanos Zafeiriou

The obtained results show premise for utilization of the extended Aff-Wild, as well as of the developed deep neural architectures for visual analysis of human behaviour in terms of continuous emotion dimensions.

Emotion Recognition

Training Deep Neural Networks with Different Datasets In-the-wild: The Emotion Recognition Paradigm

no code implementations12 Sep 2018 Dimitrios Kollias, Stefanos Zafeiriou

A novel procedure is presented in this paper, for training a deep convolutional and recurrent neural network, taking into account both the available training data set and some information extracted from similar networks trained with other relevant data sets.

Emotion Recognition

A Multi-component CNN-RNN Approach for Dimensional Emotion Recognition in-the-wild

no code implementations3 May 2018 Dimitrios Kollias, Stefanos Zafeiriou

This paper presents our approach to the One-Minute Gradual-Emotion Recognition (OMG-Emotion) Challenge, focusing on dimensional emotion recognition through visual analysis of the provided emotion videos.

Emotion Recognition

Cannot find the paper you are looking for? You can Submit a new open access paper.